Interchangeable counterbore.



P. S. WALTERS. INTERCHANGEABLE COUNTERBORE. APPLICATION FILED JAN.11,1911.

(UNITED srxrss IRANGIS'S. WALTERS, or WILKINSIBURG, TOOL COMPANY, or CLEVELAND INTERCHANGEAB To all :w'kom it may concern Be it known that I, FRANCIS S. WALTERS,

invention are equally applicable to reamers and other cutting tools of like nature.

The object of the invention is to provide a tool in which a single shank may be provided with any one of a plurality of cutters of different size or in which the cutter may be removed from the shank for sharpening without removing the shank from the machine in which it is mounted, and in which the cutter will always be positively and exactly centered with respect to such shank when placed in operative position thereon. a

Another object is the provision of a tool which shall embody, together with the above features, an interchangeable pilot, or centering device, which may be employed with any of the cutters with which the tool may be equipped, and which may be of any desired diameter or length dependent upon the work to be performed, and which shall serve both to center the cutter upon the shank and with regard to the work.

,Other objects-and advantages of the invention will appear from the following description and claims.

One embodiment of my invention is illustrated' in the accompanying drawings, in which:

Figure 1 is a longitudinal sectional view of theassembled tool; Fig. 2 is a side elevation of the same; and Fig. 3 is a perspective view of the cutter.

Describing the parts by reference characters, 1 indicates the shank, having at one end a portion 2 shaped for engagement in a lathe-chuck, turret-head, or drill press, and having at the other end a threaded boss or projection 3 for the reception of the cutter 4. The axis of the boss is in strict Specification of Letters Patent.

Application filed January 11, 1911.

PENNSYLVANIA, ASSIGNOR T0 NATIONAL OHIO, A CORPORATION OF OHIO.

LE COUNTERBORE.

Serial No. 602,028..

alinement with the axis of the shank and is formed 'with an axial socket 5, which extends well into the shank. At its forward end the shank preferably terminates in an abrupt shoulder 6, and between this shoulder and the threaded portion of' the boss a conical portion 7 is formed.

The cutter is of cylindrical form and has teeth or edges 8, the same being backed off in the usual manner, and having the front face of each tooth separated from the back of the preceding tooth by the inclined or spiral groove 9, the angle of such groove being of the degree necessary to give the required inclination or rake. An axle hole 10 is formed through the cutter, the -forward portion thereof being of exactly the same diameter as the recess 5, and the rear portion thereof being enlarged and threaded as at 11, to receive the threaded boss 3. The

as at 12 complementarily to the conical portion of the shank and is adapted to be seated and centered thereon, the rear end of the cutter, outside said fiared portion being squared as at 13 and extended outwardly to a diameter sufficient to provide therequired stren th at this point. .The angle of slope neighborhood of 30, and the threads inthe recessed portion 11 terminate a little short of the extremity of the flared portion so as not to engage the end of the-cone. In order to prevent the spreading e'ifect'of the conical portion 7 from splitting the cutter, the rear end thereof may be hardened to a less de-- gree than the forward end as indicated by teeth of the required hardness combined with of my invention.

At the outer end of the cutter the grooves 9 are preferably cut entirely through into the hole 10 soas to form notches 14: which chips and also markedly facilitate the sharpening of the cutters. As the cutters are ground down this groove is also cut out so as always to provide these notches. The cutting edges may either be square with the axis as illustrated, or may be at an angle Patented Jan. 30,1912.

outer rear end of this enlargement is flared of th s conical portion is preferably in'the Y the difference ir density of the cross hatching in Fig. 1. This expedient provides serve to permit a more perfect clearance for at its forward end a plurality of cutting a body of great toughness, though such an arrangement is not essential to the practice l -lfl'ti) {5i Witt he oh'vio 2, 1d their 121112 Toe eltrer greater or :Imrmder the."

shown.

The pilot is indicated at 15 m comprises :1 shank i6 secure fitting hole through the cotter and t: and he 'tlet side adapted to he engaged by th screw 1&1 This flntt ed. portion is p]. v ehlytspered forward to term a more secure hearing. The head 0; 1e pilot may he made of any desired size and several sizes of piriot be provided with each cutter, depend ing upon the neeessity of the Work, In fact the head may he of sn'mtler dhalmeter than the shank if desired though the need of this combination. will be less frequently perieneed- Upon screwing the cutter upon the shard; the rear end will he eeeumtely centered by the engagement of the eooiord portions, notwithstanding any slight gnleriiy of m threads, and the piiot shmt: will acorn-stew eenter the forward end of the cutter as regards 1 eel shank. ,1 if {claim is:

. 1 e ooontertmre or like tooh the eom-- twmtlon Witt). a some ham-mg :1 threaded v at hoss its forward end and an axial I recess opening through said boss, of a removable cutter hzrving an axial perforation adopted to? ahoement with said 1 tees and a threaded socket ihrjfiied to receive snio bossn and :2 pitot 1 ing' a shank adopted 7 1 size to Ft srm within said cotter perior whereby s: r titer may he :tered 1 said aid oot shen EUOH 53-. 1'11 oomirterhore or like tool, the combh'mtion, 'a'vith :1 shout: having a. threaded. axial boss its forward. ende,nd conicalor flaring portion at the base of said boss and. also having an axial recess opening through said boss, of a, cutter having a threaded socket adapted to receive said threaded boss, the outer portion of said socket being flared complementarity to the conical 1 ;-tion of said shank and adapted to soot flhlCOi], said cutter also having an axial bore of the same dimneter as said reeess and adopted to he brought into ahnement therewith when said cutter is screwed upon said hose, and a, pilot having a shank adapted to pass through and closely fit said bore and to be secured in said recess.

:5.v In av counterhore, the combination, with a shank havinga threaded axial boss at its forv-iaird end and a, conical or flaring portion base of said boss, of a cutter having cutting teeth at its forward end and having at. its rearward end an internally threaded ax'al socket adapted to receive said thremted boss the outer portion of said socket heiog flared oomplementarily to the conical portion of said shank and adopted to seat thereon, the rear end oi said cutter being hardened to a tess degree than the forward end thereof.

In testimony wi'lereoit, it hereunto sflix my signature in the presence of two witnesses.

FELLXNCIS 55. HALTER-S. 

